scholarly journals Thermal Decomposition of Tobaccos: VII: Influence of Atmosphere on the Formation of Gas Phase Constituents

Author(s):  
H. R. Burton ◽  
G. Childs

AbstractFormation profiles have been obtained for methane, ethane, ethene, propane, propene, butanes, butenes, isoprene, formaldehyde, acetaldehyde, acetone, 2-butanone, benzene, and toluene from the thermal decomposition of tobacco in the presence of helium and air. These data show that in helium the temperatures for optimum formation of gas phase constituents were: hydrocarbons, 450°C; aldehydes, 300°C; ketones, 450°C; isoprene, 380° and 475°C; and aromatic hydrocarbons, 450°C. Air enhances the formation of these gas phase constituents at 280°C and in most cases at 420°C, the latter temperature is an area of major weight loss of tobacco. Each formation maximum corresponds to a rate of weight loss maximum exhibited by derivative thermogravimetry. The results also show that it is possible to use effluent gas analysis to define the thermal behaviour of tobacco in terms of the formation of the gas phase constituents which provide a means to elicit the processes that occur during the thermal decomposition of tobacco.

2007 ◽  
Vol 32 (4) ◽  
pp. 49-54 ◽  
Author(s):  
A. B. Siqueira ◽  
C. T. de Carvalho ◽  
E. C. Rodrigues ◽  
E. Y. Ionashiro ◽  
G. Bannach ◽  
...  

Solid State Ln-L compounds, where Ln stands for light trivalent lanthanides (La - Gd) and L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-Ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, ligand denticity, thermal behaviour and thermal decomposition of the isolated compounds.


2018 ◽  
Vol 34 (2) ◽  
pp. 15
Author(s):  
Adriano Buzutti De Siqueira ◽  
Cláudio Teodoro De Carvalho ◽  
Elias Yuki Ionashiro ◽  
Massao Ionashiro

Solid state M-L compounds, were M stands for bivalent Mn, Fe, Co, Ni, Cu, Zn and L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-Ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, ligand denticity, and thermal decomposition of the isolated compounds.


2004 ◽  
Vol 29 (1) ◽  
pp. 31-40 ◽  
Author(s):  
G. Bannach ◽  
E. Schnitzler ◽  
C. B. Melios ◽  
M. Ionashiro

The synthesis of sodium 2-chlorobenzylidenepyruvate and its corresponding acid as well as binary, binary together with it's acid or hydroxo-2-chorobenzylidenepyruvate of aluminium (III), gallium (III) and indium (III), were isolated. Chemical analysis, thermogravimetry, derivative thermogravimetry (TG/DTG), simultaneous thermogravimetry-differential thermal analysis (TG-DTA) and X-ray powder diffractometry have been employed to characterize and to study the thermal behaviour of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition.


2009 ◽  
Vol 34 (2) ◽  
pp. 15-21
Author(s):  
A. B. Siqueira ◽  
C. T. de Carvalho ◽  
E. Y. Ionashiro ◽  
M. Ionashiro

Solid state M-L compounds, were M stands for bivalent Mn, Fe, Co, Ni, Cu, Zn and L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-Ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, ligand denticity, and thermal decomposition of the isolated compounds.


Author(s):  
Jako S. Eensalu ◽  
Kaia Tõnsuaadu ◽  
Jasper Adamson ◽  
Ilona Oja Acik ◽  
Malle Krunks

AbstractThermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aqueous solution of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, differential thermal analysis and evolved gas analysis via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) measurements, and quantified by NMR and elemental analysis. Solid intermediates and final decomposition products of 1 prepared in both atmospheres were determined by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compound, where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degradation of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomposes at 90–170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO 2 2− ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decomposition mechanism of 1 is described with chemical reactions based on EGA-MS and solid intermediate decomposition product analysis.


2017 ◽  
Vol 23 (38) ◽  
pp. 9018-9021 ◽  
Author(s):  
Pierre-Emmanuel Alexandre ◽  
Alexander Schwenger ◽  
Wolfgang Frey ◽  
Clemens Richert

1992 ◽  
Vol 286 ◽  
Author(s):  
Takeshi Okutani ◽  
Yoshinori Nakata ◽  
Masaakt Suzuki ◽  
Yves Maniette ◽  
Nobuyoshi Goto ◽  
...  

ABSTRACTSiC fine particles were synthesized by the gas-phase thermal decomposition of tetramethylsilane (Si(CH3)4) in hydrogen under microgravity of 10−4G for 10 sec. Rapid heating to the temperature over 800°C which is required for thermal decomposition of Si(CH3)4) under short-time microgravity was attained using a chemical oven where the heat of exothermic reaction of combustion synthesis of Ti-A1-4B composites was used as the heat source. Monodisperse and spherical SiC fine particles were synthesized under microgravity, whereas aggregates of SiC fine particles were synthesized under 1 G gravity. The SiC particles synthesized under microgravity (150-200 nm) were bigger in size and narrower in size distribution than those under 1 G gravity (100-150 nm).


Sign in / Sign up

Export Citation Format

Share Document